Write $2 ^ { - 4 }$ Using a Positive Exponent $2^4$

Multiple Choice

Write $2 ^ { - 4 }$ using a positive exponent.

A) $2^4$
B) $\left( \frac { 1 } { 2 } \right) ^ { 4 }$
C) $\left( \frac { 1 } { - 2 } \right) ^ { 4 }$
D) $( - 2 ) ^ {- 4 }$